A portable jack is often stored in a motor vehicle to enable a driver to lift the vehicle to effect emergency repairs such as, for example, changing a tire. One type of portable jack for automobiles is a pantograph scissors jack. Pantograph jacks typically have four arms hinged at four joints to form a parallelogram or pantograph. One joint is formed on a base which rests on the ground while another is positioned at a load rest located vertically above the base. The other two joints are free floating and are located on a horizontal diagonal at opposite sides of the parallelogram formed by the arms. When the free floating joints are drawn together, the arms extend vertically to lift the load support relative to the base. The position of the free floating joints, and thus the load support, is controlled by a drive screw or threaded shaft which links them together.
There is continuing emphasis by automobile manufacturing companies to reduce the size and weight of components. In turn, jack manufacturing companies are continuously attempting to reduce the size and weight of jacks while still providing adequate strength to bear required loads. Jack manufacturers are also continuously attempting to improve the performance and life of jacks. Accordingly, there is a continuing need for an improved jack for use with motor vehicles.